Rigid body bursting and clustering
Your cubes are sticked to each other, so you must be sure that the Sensitivity &gt; Margin is at 0. So give Margin &gt; 0 to one of the cubes, select all the cube, select the one with 0 at the end to make it active, go into the header menu &gt; Object &gt; Rigid Body &gt; Copy From Active and it will work: